It’s a development to be filed in the drawer marked “utterly predictable”.

As the UK slides inexorably towards departure, next year, from the European Union, First Minister Nicola Sturgeon has insisted that the SNP cannot support the Westminster Government’s EU Withdrawal Bill. To do so, she said, would not be in Scotland’s “national interest”.

To the sizeable minority of Scots who remain fiercely loyal to the nationalists, Sturgeon’s position surely demonstrates exactly the sort of principled politics they’ve come to expect from a party whose “standing up for Scotland” message remains potent.

To others, those who hoped the matter of Scottish independence had been settled by the result of the 2014 referendum, the First Minister’s stance might seem less noble. A nationalist leader, after all, is never happier than when she’s riding the constitutional rapids and the more turbulent the course, the better.

The withdrawal bill has already been altered by the UK government to include a sunset clause limiting the period of time that Westminster could retain all powers that will return from Brussels after Brexit. But while this was enough to win the support of the Welsh Assembly, Holyrood looks likely to remain opposed. The SNP and their fellow nationalists, the Scottish Green Party, are almost certain to see to that.

The withholding of support for the withdrawal bill will not scupper it; the backing of devolved administrations would simply create a show of unity behind whichever version of Brexit Prime Minister Theresa May is able to negotiate.

This being so, the First Minister’s opposition was inevitable. Where would be her political prize for standing beside the Prime Minister on this issue?

In the immediate aftermath of the UK’s June 2016 vote to leave the European Union, Sturgeon believed the cause of Scottish independence had been reinvigorated. Scots – a majority of whom had voted Remain – were being dragged out of Europe against their will and, in defiant response, they (or some of them, at least) would forget their previous support for the maintenance of the UK and throw their lot in with the SNP.

This did not come to pass. Instead, poll after poll shows that support for independence remains stalled. Moreover, senior party figures accept that their constant talk of a second independence referendum was a key factor in the SNP’s loss of 21 Westminster seats in last year’s snap general election.

But in this particular constitutional row, the First Minister may enjoy a little more support. Almost two-thirds of Scots voted Remain in 2016. I dare say many who do not share the First Minister’s view on Scottish independence will see her position on the matter of withdrawal from the EU as entirely legitimate.

Opposition parties at Holyrood should be wary of allowing the First Minister to keep the withdrawal bill at the centre of Scotland’s political debate. Every moment that they do, they take the focus off the SNP’s real problem – the state of the domestic agenda.

It certainly suited Scottish Conservative leader Ruth Davidson to make the constitution central to her campaigns in both the 2016 Holyrood and 2017 Westminster elections. Her vocal opposition to a second independence referendum resulted in the Scottish Conservatives leapfrogging Labour to become the country’s second most popular party.

It would be foolish to question Davidson’s strategy – the evidence of its success is stamped on the forlorn faces of Labour politicians who, little more than a decade ago, could count on vehement opposition to the Tories to maintain their own position as the dominant force in Scottish politics.

But if her position on a second referendum was enough to slow – perhaps even derail – the SNP’s independence express, if she is to inflict further damage on the party, then the ammunition she requires is elsewhere.

After the Tories’ success killed off the prospect of a second independence referendum any time soon, Scotland’s political debate moved, for what seemed the first time in living memory, firmly back on to those everyday issues – education, health, crime – that actually matter to voters.

Davidson’s refrain that the First Minister should “get on with the day job” instead of obsessing over rerunning a constitutional battle that she had lost drew a link between the SNP’s priority – campaigning relentlessly for Scottish independence – and substandard services. If hospital treatment targets were not being met or pupils were failing to achieve acceptable standards in literacy and numeracy, these were the consequences of government by a party which cared only about breaking up the UK. Hardly subtle stuff, but protected by a ring of truth.

Ask an SNP cabinet secretary what the party has done for Scotland and they will, doubtless, tell you about the abolition of prescription charges for all and proclaim the benefits of free tuition fees for Scottish students.

But these oft-quoted achievements – the merits of which are eminently debatable – are the oldest of news. Free prescriptions and tuition fees are totems standing in a desert.

We know – because former SNP justice secretary Kenny MacAskill has, on more than one occasion, told us so – that the Scottish Government has allowed the independence cause to influence decisions taken in other areas. The nationalists in government have always been wary of rocking the boat to the detriment of their central mission.

This fear of risk has meant that, during 11 years of rule at Holyrood, the SNP has shied away from any kind of reform in key areas. There was Police Scotland, I suppose, but that hardly ranks as the nationalists’ finest achievement, does it?

Every minute that Sturgeon maintains her relevance to the Brexit debate by furiously rejecting the withdrawal bill is a minute when the Scottish Government’s record goes unexamined.

Davidson may have got where she is today by talking about independence as often as the First Minister does, but if she wants to go further still, her focus should return to the bread and butter issues on which the SNP is failing.